Sikorsky, part of Lockheed Martin Corp (LMT), and Germany's Rheinmetall AG (RHM.XE) will team up for the German air force's new heavy-lift helicopter competition, presenting Sikorsky's CH-53K aircraft, the companies said Tuesday.

The CH-53K is used for humanitarian aid and troop transport, among other missions, and the U.S. Marine Corps will field it as a fully operational aircraft in 2019, Sikorsky said.

The companies said they're looking into leading a team with more German partners, to provide maintenance, training and other support to the helicopter program.